Knurling tools



July 9, 1957 A. BENNETT 2,798,391

KNURLING TOOLS Filed Sept. 20. 1952 2 Sheets-Sheet l f ln July 9, 1957A. BENNETT 2,798,391

mmm@ TooLs Filed Sept. 20f 1952 2 Sheets-Sheet 2 l l [244 /yp f 422 Ilm5 vg he@ 52 35 23.2; l? j 2F j I 36 22 i fly 57% 1312/ 9 55. y w 55 5g50 United States Patent Of KNURLmG 'rooLs Anthony Bennett, Niles, Ill.,assignor to Porto .Knurling Tools, Inc., Chicago, Ill., a corporation ofIllinois Application September 20, 1952, Serial No. 310,679

4 Claims. (Cl. Sil-5.1)

This invention relates to improvements in knurling tools and it consistsof the matters herein illustrated and described and more particularlypointed out in the appended claims.

The invention is more particularly concerned with tools for knurling thesurface of a worn bore in a work piece to raise the metal of saidsurface and provide a better tit of parts, such as a bearing, a bushingor a journal employed in the bore.

One of the objects of the invention is to provide a tool especiallyadapted for manual operation, in knurling the worn surface of a bore ina work piece and which tool is simple, strong and rigid in constructionand is efficient in its use in raising the surface of bores of severaldifferent diameters and axial depths.

Another object of the invention is to provide a tool of the kindmentioned, wherein the knurls are forced into engagement with thesurface of the bore by means of a wedge-like member which when turnedVabout its axis causes the knurls to travel around and raise saidsurface.

The above mentioned objects of the invention, as well as others, alongwith the advantages thereof, will more fully appear as the specicationproceeds.

In the drawings:

Fig. l is a perspective view of the two main operating parts of thetool, arranged in an axially separated position.

Fig. 2 is a horizontal sectional View through the improved tool as takenon the line 2-2 of Fig. l, with the wedge member of the tool engagedwith the inner end of the knurl carrying bars of the tool to force theknurls outwardly into operative engagement with the surface of a bore ina work piece.

Fig. 3 is a plan view of the main body member of the tool.

Fig. 4 is a vertical sectional View through the tool as taken on theline 4 4 of Fig. 2.

Fig. 5 is a top View of the wedge member of the tool.

Fig. 6 is a perspective view of one of a number of knurl carrying barsforming a part of the tool.

In general, the improved tool comprises a body assembly and a coactingwedge-like member or drift. The body has a center hole therethrough anda plurality of arcuately spaced peripheral parts separated byintermediate peripheral parts. The body also includesradial guidepassageways that open at one end into the center hole and at the otherend through an associated rst mentioned peripheral portion. A bar is sodisposed in each passageway that it may slide radially but cannot turntherein. The inner end of each bar normally extends into the center holeand the other or outer end carries a rotative knurl. Each intermediateperipheral portion is made to provide a guide arranged parallel with theaxis of the hole, to adjustably receive a body supporting member thatterminates at its upper end as an outwardly extending arm which engagesthe work piece Patented July 9, 1957 outwardly of the bore, the surfaceof which is to be raised By adjusting the arms with reference to thebody, the latter may be supported at desired elevations in the bore withthe knurls engaged with the surface of the bore.

These bars and the body are so correlated that there may be employedtherewith some resilient means normally tending to yieldingly retractthe bars relative to the passageways and at the same time limit thisretraction of the bars.

The wedge-like member, which is separate from the body, may be insertedinto an initial position in the center hole thereof. This member has atapered body and a plurality of radially extending ribs which engage inrecesses in the body that open into the hole and whereby when the memberis turned axially causes the body to turn therewith. Parts of thetapered body of said wedge member, when in said initial position, engagethe inner ends of the bars which are also tapered for engagement by saidparts of the wedge member body. The top end of said wedge member has atapping head whereby the wedge member may be further driven, as by meansof a hammer, into said hole so as to extend the bars and press theknurls against the surface of the bore to be raised. This tapping headis so made as to receive a bar-like wrench and whereby said member maybe turned axially and cause the body to turn therewith, with the knurlsso engaged with the surface as to raise and renew the same.

Referring now in detail to that embodiment of the invention illustratedin the drawings, the improved tool comprises a body assembly 1t) and awedge-like member 11, the former being made up of a number of correlatedparts, as will hereinafter appear, and the latter consisting of only asingle part. Said body assembly and said wedge-like member appear bestin Fig. 1.

The body assembly includes a main body part 12 which best appears inplan in Fig. 3. This body is of a truncated triangular shape and has acenter hole 13, a plurality of arcuately spaced, concentric peripheralportions 14 and a plurality of straight intermediate peripheral portions15, each portion 15 being diametrically opposite a peripheral portion14. In each peripheral portion is a radial passageway 16 which opens atits outer end through said peripheral portion and opens at its inner endinto the center hole 13. Each passageway is of a rectangular crosssection, there being at each side of the outer end thereof an enlargingrecess 17. In that part of the top of said body in the center line of apassageway is an elongated opening 13 that communicates with saidpassageway for a purpose to appear later. On the center line of eachpassageway and in that side of the hole opposite the inner end of thepassageway is a groove 19 that opens into the center hole. In the centerpart of each peripheral portion 15 is a longitudinally extending shallowgroove 20 and centrally between the ends of this groove is a threadedopening 20a.

Engaged in each passageway 16 is a bar 21 which can move longitudinallybut cannot turn therein and one of said bars best appears in perspectivein Fig. 6. This bar, which is longer than the distance between the boresurface of the hole 13 and the associated peripheral portion 14 of thetool body, has a slightly inclined inner end surface 22 and it isbifurcated at its outer end to receive a knurl 23 that is operativelysecured in place by a vertical journal pin 24. About centrally of thetop surface of each bar is a recess 25, each of which receives a limitpin 26 that slides in an opening 1S. A helical tension spring 27 passesaround the outside of each of the limit pins and normally acts toretract them inwardly of the body until limited by the engagement of theassociated pin 26 with the inner end of its slot 18.

Each groove 20 receives, for guided adjustable movement, the uprightpart 30 of an associated inverted L- shaped body supporting member 31,the upper end of which includes an outwardly extending arm 32, having arounded bottom for engagement on that part of a work piece 33 about thebore 34 therein, the surface of which it is desired to raise. Theupright part 30 of each supporting member 31 has a longitudinal slot 35therein for the passage therethrough of a retaining screw 36 thatthreads into the associated opening 20a in the tool body. A washer 37 isdisposed between said part 30 and the head of the screw so that whensaid screw is drawn up tight the supporting member is rigidly fixed tothe body. By loosening the screws 36, the supports 31 may be adjustedupwardly or downwardly to provide the desired elevation of the body `12in the bore 34 in an operation of the tool. The underside of each arm 32is concaved so that it can ride on the work piece 33 without catchingthereon as the tool, as a whole, is turned in an operation thereof. Thespring 27 also passes around each upright part of each support 31 asbest appears in Fig. l.

When the bars 21 are in their innermost retracted positions, sideportions of the associated knurl engage in the recesses 17 at the sidesof the outer end of the associated passageway 16.

The wedge memberV 11 includes a tapering body 40 with a cylindricalupper part 41 that terminates in Va top end tapping head 42 in which isformed a rectangular socket 43. This socket receives a rectangular bosson the bottom end of the body 44 of a T-shaped actuator which includesat its upper end a pair of oppositely extending, turning handles 45.Extending about the full length of the body of the wedge member, whichhas a taper corresponding to the angle of the inner end face 22 of thebars 21, are radially disposed ribs 46, the outer edges of which areparallel with the axis of the wedge member. These'ribs are so arrangedabout said body as to register with the grooves 19 in the body 12 andthe bottom end edges of said ribs are slightly rounded as are the bottomend corners thereof so as to pilot these ribs into said recesses in theoperation of the tool. When the body assembly is disposed in a bore 34of a work piece 33, it is supported by the arms 32 of the supportingmembers 3,1, which arms then engage upon the surface of work outside andbeyond the surface of the bore as best appears in Fig. 4. The bottom endof the member 11 is then inserted into the hole 13 with the ribs 46engaged in the grooves 19 of the body and with surface parts Iof thesmaller bottom end lof the body engaged `with the inner end surface ofall of the bars 21. This is the initial position of the parts in a tooloperation. v

By means of a hammer, tapping gently on the head 42 of the wedge member,the latter is driven inwardly of the hole and because `of the taperedsurfaces before mentioned, the bars 21 are extended -or forced outwardlyto press the knurls 23 forcefully against the surface of thebore. It ispointed out that as the bars are extended outwardly, the pins 26 thereofexpand the spring 27. However, the angle of taper and inclination of thesurfaces of the body and the inner end surfaces 22 of the -bars 21 aresuch that the spring cannot cause the arms to retract to such an extentas to lift the wedge member out of this position.

The T-actuator is then applied to the wedge member, after which theoperator grasps the handles V of the actuator and turns the same. Byreason of the ribs 46 this turning movement of the wedge member is`transmitted to the tool body assembly 10 and causes it to turn. In thisturning movement of the body assembly, the knurls 23 travel about thesurface of the bore and displace portions thereof whichin effect raisesthis part ofthe surface. After the surfacehas thus been raised, the toolmay be removed, afterloosening Athe grip of 4 the wedge member andwithdrawing the same upwardly in thei hole 13. Y v

By loosening the screws 36, the position between the body 12 and thearms 32 of the supports 31, may be altered to change the elevatedposition of the tool assembly in the bore for another operation, whichat said different elevation, increases the area of the band of knurlingformed in said surface.

Thereafter the toolV is again actuated as before described.

I claim as my invention:

l. A tool for knurling the' bore of a work piece embodying'therein Yatool'body in'sertable into said bore and having a center hole, meansoperative to support said body from lthe work piece, a plurality ofmembers having guided movement relative to the body inwardly andoutwardly of said opening and each carrying a knurl at its outer end foroperative engagement with the surface of said bore and each having aninner end disposed in said hole, said body having a. plurality ofrecesses disposed between said members and `opening into said hole, awedge-like member for axial insertion in one direction into an initialp'osition in said hole, said wedge-like member having a tapered body anda plurality of radial ribs, the body of the wedge-like member havingparts between said ribs for engagement with the ends of said knurlcarrying members and said ribs being adapted for engagement in saidrecesses, said wedge-like member when moved yaxially further into saidhole operating through said parts between said ribs to extend said knurlcarrying members to press said knurls against said surface of the bore,said ribs in the turning movement of `the wedge-like member imparting aturning movement to the Ytool body to cause the knurls to travel aroundsaid surface.

2. In a portable knurling tool having a tool body with adju-stableknurling elements and a combination adjusting and driving member, saidmember comprising a plurality kof circumferentially spaced faces, saidfaces tapering towards one end thereof, axially extending barsseparating adjacent faces, said `bars projecting radially outward fromthe faces and a lsocket at one end of said member adapted to receive anactuator, whereby said faces are arranged to control adjustment of theknurling elements and said bars are arranged to drive the tool body.

3. kIn a portable knurling tool having a combination adjusting anddriving member and a tool body, said tool body having a center hole, aplurality of outer peripheral faces, said outer faces being concentricwith said center hole, a plurality of 4straight intermediate facesbetween said peripheral faces, each straightface being diametricallyopposite a peripheral face, a plurality of lradially extendingguideways, one each communicating said center hole with an outerperipheral face, a bar slidably received in each guideway, each barnormally having one end protruding into said center hole and the otherend'extending outward from a peripheral face, a knurling element mountedon said other end of each bar, ythe very inner end of each bar adaptedto engage the adjusting and driving member, means for normally urginglsaid bars radially inward, and axially extending grooves opening intothe center hole for receiving the adjusting and driving tool.

4. In a portable knurling tool having a tool body and acombinationadjusting and driving member, said tool body having a center hole, aplurality of Vouter peripheral faces, said outer faces being concentricwith said center hole, a plurality of straight intermediate facesbetween said peripheral faces, each straight face being diametricallyopposite a peripheral face, a plurality of radially extending guideways,one each communicating said center hole with a peripheral face, a barslidably received in each guideway, each bar normally having one endprotruding into said center hole and the other end extending outwardfrom an outer peripheral face, a knurling element mounted on said otherend of each bar, the very inner end of each bar adapted to engage theadjusting and driving member, means for normally urging said barsradially inwardly, and axially extending grooves opening into the centerhole for engaging the adjusting and driving tool, said combinationadjusting and driving member comprising a plurality of circumferentiallyspaced knurling element adjusting faces, said faces tapering towards oneend of said member and adapted to engage the very 10 inner end of saidother ends of said bars, axially extending drive bars separatingadjacent faces, said bars projecting radially outward from the faces andadapted to be slidably received in said grooves of the tool body and asocket at one end of said member adapted to receive an 15 5 to said toolbody.

References Cited in the tile of this patent UNITED STATES PATENTS128,260 Taylor June 25, 1872 480,435 McGraw Aug. 9, 1892 1,837,624Maupin Dec. 22, 1931 1,931,882 Bartels Oct. 24, 1933 2,409,219 MaxwellOct. 15, 1946 2,618,182 Teetor Nov. 18, 1952

